In the construction industry it is frequently necessary to make plumb cuts. For instance, during the construction of a building, carpenters and other persons working on the site measure and secure together pieces of dimension lumber to form a structure. During the course of measuring and assembling the lumber to form a structure, it may be necessary to make angled cuts in the lumber, and a variety of measuring tools are available for appropriately marking the lumber which can then be cut along the mark by using a power or hand saw.
In the construction of a roof, for example, boards are supported near their lower ends on the top edge of a wall and extend upwardly to a ridge line where they are secured to like boards extending upwardly from an opposite wall. These boards serve as rafters in the roof structure of a building. It is common practice in the prior art to install rafters with the lower or tail ends cut perpendicular to the longitudinal axis of the rafter and after all of the rafters are installed to strike a chalk line along a top or bottom edge of the rafters and then mark each rafter by using an appropriate hand tool to provide a plumb or vertical line at the lower end of each rafter. A carpenter then uses a saw to cut along the marked plumb lines to provide an appropriate angle on the tail ends of the rafters. This procedure requires several time consuming steps, adding to the cost of the project.
Similarly, it is frequently necessary to make angled cuts at the upper ends or ridge line of the rafters or in other structures, including hip-roof constructions and the like.
As presently practiced, all of these special cuts require careful measuring and marking followed by cutting along the marked lines with an appropriate tool, such as a power hand saw.
Accordingly, there is need for a device which will enable angled cuts, and especially plumb cuts, to be made without first marking a line along which the cut is to be made.